Lenses & Filters

[jimd]

Here is my question: Do I need a separate set of filters for each lens I want to use on my camera, or is it okay to put the filter behind the lens?

I have a Canon S3 IS, which has 58mm threads. So I bought a few 58mm filters. Now what happens when I use a wide-angle or tele-photo lens? Do I attach the lens right on top of the filter, or do I remove the filter, attach the lens, then put a filter on top of the lens? (requiring a different size filter).

I would like to keep the same set of filters I have instead of buying a whole different set for each lens, but I didn't know if having the filter behind the lens will affect the photo at all. Does anybody know what the best practice is in this situation?

[photobyfelix]

Here is a website that discusses filters. I found it just this afternoon. Down neqar the bottom of the page is a discussion on controlling costs, which may help you. Basically, if your filter set is for your bigest diameter lens, you can buy adapter rings to use the big filter on smaller diameter lenses.

[jimd]

photobyfelix, did you forget to include the link?
using the largest mm filter with the smaller lenses & step-down ring makes total sense. Thanks for the tip.